1. Field of the Invention
The present invention relates to oil absorbent silver skin-containing paper having a low water absorbency and a method for producing the same, and specifically to silver skin-containing paper and a method for producing the same, wherein coffee silver skin discarded during beverage production is effectively used for paper manufacture to provide oil absorbent paper having a low water absorbency.
2. Related Art
In the preparation of beverages such as teas including green tea and black tea, coffee, and juices, fine refuse or extraction residues of tea leaves, coffee grounds, etc., are discarded as wastes. Much of coffee beans distributed for ordinary households or coffee shops are provided to the market after roasting green coffee beans in roasting plants or the like, and a great amount of coffee roasting residues are discarded from the roasting plants. Also in the tea roasting process, roasting residues and fine grounds are discarded. From the viewpoints of environmental protection and effective utilization of resources, methods for effectively utilizing these wastes have been studied.
For example, Japanese Patent Application Laid-Open (JP-A) No. 4-82999 discloses patterned paper containing coffee extraction residues or ground roasted coffee beans having an average particle size of 3 mm or less. JP-A No. 6-235198 discloses patterned paper containing tea leaves or tea grounds of, for example, black tea, green tea or oolong tea, as pattern formers. In order to solve the problems regarding the workability during sheet forming and the hardness of the material, JP-A No. 8-158298 proposes micronization of vegetable matter including stems and leaves to a size of 1 to 100 microns.
JP-A Nos. 10-248409 and 2000-128731 disclose paper mulch sheets made of paper pulp containing a carbon powder made from coffee grounds, proposing to effectively utilize adsorptivity of carbon.
Examples of other applications include an oil absorbent as disclosed in JP-A No. 2001-000858, which is made by attaching a water-repellent silica powder to coffee grounds or the like. JP-A No. 2000-139257 discloses coated particles for treating small animal wastes, wherein the coated particles are made by coating a core made of a ground product of vegetable organic fibers such as rise husk, with a superabsorbent polymer and a paper powder. Examples of the useful organic fibers include silver skin as well as peat moss, coconut fibers, tree bark, and shell and skin of peanuts.
As described above, various applications have been developed for the bean portion including coffee beans and extraction residues. On the other hand, few applications have been developed for silver skin discarded during coffee roasting, and there is inadequate utility for accepting the recycle of the wastes. Accordingly, further development of the treatment methods and applications for the wastes has been demanded.